Coating powders are dry, solventless powders used to coat various metallic objects, including wire. To coat wire the powder is fluidized and charged while the wire is grounded. The charged powder clings to the wire and is melted in an oven to form the coating.
Coating powders have many advantages over wire enamels. Wire enamels require a solvent which means that energy must be used to evaporate the solvent and to incinerate it to prevent it from polluting the air. Also, a wire enamel coating must be applied in several passes which means that the start-up wire, which has not had the full number of passes, must be scrapped. While wire enamels have much superior heat shock resistance to coating powders, so far all efforts have failed to produce a coating powder having the chemical structure and therefore heat shock resistance of a wire enamel.